Conventionally, an electromotive valve timing control device, which is configured to control an engine valve timing by utilizing a rotation torque of a motor, is known. In such an electromotive valve timing control device, a planetary rotor connects a driving side rotor, to which torque of a crankshaft is transmitted, with a driven side rotor, which transmits torque to a camshaft. The motor of the valve timing control device manipulates a rotation speed of the planetary rotor relative to the driving side rotor. Thus, the motor of the valve timing control device manipulates the phase of the driven side rotor relative to the driving side rotor, and manipulates an opening-and-closing timing of a valve, which is opened and closed by the camshaft.
Such a valve timing control device may include an electronic component accommodation member to accommodate an electronic component of the control circuit. In such a configuration, the electronic component accommodation member restricts rain water from adhering to a control circuit of a motor drive control unit, which controls the motor. A patent document 1 discloses an electronic component accommodation member, which has an air introduction portion and a ventilation filter. The air introduction portion forms an air introduction passage, which communicates an outside with an accommodation space, in which an electronic component is accommodated. The ventilation filter is equipped to the air introduction passage to permit vapor flow between the outside and the accommodation space. The ventilation filter further restricts liquid flow between the outside and the accommodation space.
[Patent Document 1] Japanese patent No. 3921431
It is noted that, the air introduction portion of the electronic component accommodation member described in the patent document 1 has a labyrinth configuration. Specifically, it is assumable that a water film may be formed on an outer surface of the ventilation filter. Such a water film may blockade vapor flow between the outside and the accommodation space. In consideration of such formation of a water film, the labyrinth configuration restricts water from intruding from the outside into the air introduction passage, not to avoid vapor flow between the outside and the accommodation space. Nevertheless, it is further noted that, manufacturing of the air introduction passage having such a labyrinth configuration may be costly. In the patent document 1, the air introduction portion of the electronic component accommodation member is formed of a resin material. It is further noted that, in a configuration, in which such an air introduction portion is formed of a metallic material, it is difficult to manufacture a labyrinth configuration being in a complicated shape.